Mg2+ modulates membrane sphingolipid and lipid second messenger levels in vascular smooth muscle cells

FEBS Letters

Altura, Bella T¹  Kostellow, Adele B²  Altura, Burton M¹  Ma, Gui-Ying²  Zhang, Amin¹  Morrill, Gene A²  Gupta, Raj K² 

[1] Department of Physiology, State University of New York, Health Science Center at Brooklyn, 450 Clarkson Avenue, Brooklyn, NY 11203, USA;Department of Physiology and Biophysics, Albert Einstein College of Medicine, Bronx, NY 10461, USA

关键词: Magnesium;    Phospholipid;    Sphingomyelin;    Ceramide;    1;    2-Diacylglycerol;    Smooth muscle;   

DOI  :  10.1016/S0014-5793(98)01446-X

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

In vitro studies with smooth muscle cells from rat aorta and dog cerebral blood vessels indicate that variation in free Mg²⁺, within the pathophysiological range of Mg²⁺ concentrations, found in human serum, causes sustained changes in membrane phospholipids and lipid second messengers. Incorporation of [³H]palmitic acid into phosphatidylcholine (PC) and sphingomyelin (SM) was altered within 15–30 min after modifying the extracellular Mg²⁺ ion level ([Mg²⁺]_o). Decreased Mg²⁺ produced a fall in both [³H]SM and [³H]PC over the first 2 h. After an 18-h incubation, the [³H]PC/[³H]SM ratio changed from about 20:1 to about 50:1. Increased [Mg²⁺]_o resulted in a 2- to 3-fold increase in [³H]SM compared to only a small increase in [³H]PC over the same period. There was a reciprocal relationship between [³H]ceramide and [³H]1,2-DAG levels with highest [³H]ceramide and lowest [³H]-1,2-DAG levels seen at lowest [Mg²⁺]_o. The results indicate that a fall in extracellular ionized Mg²⁺ concentration produces a rapid and sustained decrease in membrane sphingomyelin and a moderate rise in intracellular ceramide. A major effect of lowering [Mg²⁺]_o appears to be a down-regulation of SM synthase. The increased membrane SM content and a concomitant decrease in cell ceramide, in the presence of elevated [Mg²⁺]_o, may be relevant to the apparent protective role of adequate Mg intake on vascular function in humans.

【 授权许可】

Unknown